package com.freelycar.saas.iotcloudcn.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class ShaUtil {
    private static Logger logger = LoggerFactory.getLogger(ShaUtil.class);

    private static char[] CHARARRAY = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    public static String toSHA1(String str) {
        if (null == str || 0 == str.length()) {
            return null;
        }
        try {
            // ָ指定sha1算法
            MessageDigest digest = MessageDigest.getInstance("SHA1");
            digest.update(str.getBytes(StandardCharsets.UTF_8));
            byte[] md = digest.digest();
            int j = md.length;
            char[] buf = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                buf[k++] = CHARARRAY[byte0 >>> 4 & 0xf];
                buf[k++] = CHARARRAY[byte0 & 0xf];
            }
            return new String(buf);
        } catch (NoSuchAlgorithmException e) {
            logger.error(e.getMessage(), e);
            e.printStackTrace();
        }
        return null;
    }
}